Bucket for digging of narrow trenches



May 8, 1962 M. J. KAsl-IERGEN BUCKET FoR DIGGING oF NARROW TRENcRRs Filed Deo. 16, 1960 INVENTOR Mas/,41:2 Mi/655V WMM ATTORNEY United States Patent O M California Filed Dec. 16, 1960, Ser. No. 76,264 Claims. (Cl. 37-103) This invention relates to a trench-digging bucket, and to the combination with a backhoe of a bucket attachment adapted to dig narrow trenches.

An object of the invention is to provide an attachment which may be readily mounted on a conventional backhoe and which operates effectively to dig narrow trenches, for example trenches in which small-diameter pipe is to be disposed.

Another object is to provide a trench-digging attachment `for baokhoes and the like, said attachment being characterized by simplicity of construction, freedom from clogging by the earth dug thereby, rapidity and effectiveness of operation, `and the ability to make a relatively deep cut without requirement `for a large amount of power.

A further object is to provide a backhoe incorpo-rating a novel trench-digging bucket.

These and other objects and advantages of the invention will be more fully set forth in the following specication and claims, considered in connection with the attached drawing tot which they relate.

In the drawing:

FIGURE 1 is a rear perspective view illustrating a bucket attachment, constructed in accordance with the present invention, as mounted on a conventional backhoe apparatus;

FIGURE 2 is an enlarged perspective view illustrating the attachment;

FIGURE 3 is a side elevation of the bucket; and

FIGURE 4 is a section taken on line 4-4 of FIGURE 3 but illustrating the bucket as disposed in a narrow trench.

Referring first to FIGURE l, a conventional backhoe is illustrated as comprising a tractor-like frame or body 10 having large wheels 11, a boom 12 pivotally mounted on the frame 10 for pivotal movement about a vertical axis, and a dipper stick 13 pivotally mounted at the outer end of boom 12 yfor pivotal movement in a vertical plane due to operation of a dipper-stick cylinder 14. Pivotally connected to the dipper stick 13 adjacent the connection thereof to boom 12 is a bucket cylinder or ram 16.

The backhoe attachment for effecting digging of narrow trenches comprises a head or frame 18 which may be formed of strong metal elements 19 and 20 rigidly welded or otherwise connected to each other in the shape of a rectangle. The end of ldipper stick 13 is pivotally connected to head 18 as indicated at 21. Correspondingly, the piston rod portion of bucket cylinder 16 is pivotally connected to head 18 at 22. The pivotal connec tion 22 is spaced a substantial distance -from connection 21 and on the same side of the dipper stick `as that on which bucket cylinder 16 is disposed, namely the upper side or the one remote from the tractor frame 10. The pivot axes at 21 and 22 are perpendicular to the plane containing the boom and dipper stick.

Rigidly welded to head 18 below the pivot connections 21 and 22, namely to elements 20, is a strong metal bar 23. A relatively thin sheet or plate 24, of steel or the like, is welded to bar 23 along the center thereof and in depending relation therefrom, being disposed in the same plane as that ofthe boom 12 and dipper stick 13.

A plurality of arcuate strip-like metal elements 26-28, illustrated as six in number, are iixedly welded on oppo* 3,032,960 Patented May 8, 1952 ICC site sides of plate or sheet 24. In the illustrated construction, two arcuate elements 26 have relatively small radiuses and are disposed adjacent each other on opposite sides of the plate or sheet 24, being arcuate about a point in the vicinity of the pivot connection to the dipper stick. rIwo additional arcuate elements 27, having larger radiuses, are mounted beneath elements 26 in spaced relationship therefrom and are also arcuate or concentric about approximately the same point. The elements 28 have even larger radiuses, being spaced beneath elements 27, and are also arcuate or concentric about substantially the same point. Elements 26-28 are so arranged that any straight line lying in the upper surface of any one is perpendicular to sheet 24.

The plate or sheet 24 terminates at its lower portion along the arcuate elements 28, `and at its upper portion along the bar 23 as previously indicated. At its front edge portion, the plate or sheet 24 extends downwardly and forwardly from the forward end of bar 23 to the lforward ends of arcuate elements 26. Such edge portion is indicated at 29. An additional edge portion 30 extends downwardly and rearwardly from the forward ends of elements 26 along a straight line to the forward ends of elements 27 `and 28.

Cutting teeth 31 are rigidly mounted at the forward ends of the various arcuate elements 26-28, being respectively tangential thereto. As indicated by the lines A, B and C in FIGURE 3, the cutting teeth for elements 26 are substantially ahead of those for elements 27, and the cutting teeth for elements 27 are substantially ahead of those for elements 28. Thus, when the apparatus is pivoted about the pivotal connection 21 upon extension of the bucket cylinder 16, the cutting teeth for elements 26 first engage the surface of ground, thereafter those for elements 27, and thereafter those for elements 28.

Operativn In the operation of the trench-digging apparatus, bucket cylinder or ram 16 is iirst shortened in order to effect clockwise pivoting of the bucket about pivot 21. Dipper stick cylinder 14 is then lengthened in order to effect counterclockwise pivoting of dipper stick 13 until the pivot 21 is relatively adjacent the surface 36 (FIGURE 4) of the ground. The dipper stick is then maintained in substantially locked condition, and the bucket cylinder 16 is lengthened in order to eifect counterclockwise pivoting of the bucket about pivot 21.

During such counterclockwise pivoting of the bucket, the teeth 31 associated with the uppermost arcuate elements 26 rst bite into the ground and take a cut of earth. As pivoting progresses, such earth is caused to shift on both sides of the plate or -sheet 24 above the elements 26. Thereafter the teeth 31 for elements 27 take a cut of earth, which earth becomes disposed on both sides of sheet 24 between elements 26 and 27. Correspondingly, and thereafter, the teeth 31 for elements 28 take a cut of earth which is then disposed between elements 28 and 27 on both sides of sheet 24. Such sequential engagement of the teeth with the earth produces a number of benefits including the fact that a lesser amount of power is required than if all teeth engaged the earth simultaneously, it being pointed out that the teeth 31 for the lower arcuate elements 27 and 28 are in effect digging less deep due t-o the previous action of the teeth 31 for elements 26.

After such counterclockwise movement has continued until the head or frame 18 (and bar 23) is substantially horizontal, as indicated in FIGURE 3, the dipper-stick cylinder 14 is again operated to further lengthen the same and cause additional counterclockwise pivoting of the dipper stick, so that the bucket moves toward the tractor body 10. Such pivoting is continued until the bucket swings completely above the ground surface 36.

i 3 The boom 12 is then pivoted about its vertical axis until the bucket is disposed above the place where it is desired to deposit the earth. lt is then merely necessary for the operator to shake the bucket so that the earth falls over the edges of elements 26-28 and drops to the desired location. Such shaking constitutes relatively rapid manipulation of the valve controlling the boom 12.

if the earth is relatively dry, the spaces between the elements 2d and 27, and 27 and 28, do not become packed. instead, the earth is forced along the trench ahead of the bucket (toward the tractor body lil) as the dipper stick 13 pivots. On the other hand, if the earth is relatively moist, the spaces between elements 26 and 27, and 27' and 28, become relatively full of earth. The removal of such earth is, however, simple due to the absence of sides such as are found in most buckets.

As indicated above, the device is particularly adapted to be employed in digging trenches which are relatively narrow, such as 4 inches in width, for the laying of small pipe. lt is emphasized that while the bucket is in the trench, the trench walls 37 (FIGURE 4) operate as sides for the bucket.

It is pointed out that the dipper stick and the bucket cylinder may be pivotally connected directly to bar 23 or even plate 24. ln such constructions, the head is the portion of the bar or plate where the pivot connections are located.

Various embodiments of the present invention, in addition to what has been illustrated and described in detail, may be employed without departing from the scope of the accompanying claims.

I claim:

l. In combination with a backhoe having a dipper stick and bucket cylinder, a head pivotally connected to the dipper stick and bucket cylinder of the backhoe, a relatively thin support means ixedly associated with said head in dependent relationship and lying in a plane perpendicular to the axes of pivotal movement between said head and said dipper stick and bucket cylinder, and a plurality of generally arcuate narrow elongated elements iixedly mounted on at least one side of said support means in generally parallel relationship relative to each other, said elements each having tooth portions at edges thereof which are relatively adjacent the tractor of the backhoe when the bucket cylinder of the backhoe is extended, said elements extending suiiiciently far from said tooth portions to support earth above saidelements and therebetween, said elements lying in planes generally parallel to said support means.

2. The invention as claimed in claim l, in which the tooth portion of the element relatively adjacent the pivot connection to the dipper stick is disposed in advance of the tooth portion or" the element relatively remote from the pivot connection to the dipper stick, whereby said first-mentioned tooth portion engages the surface of the earth iirst and substantially ahead of the tooth portion for the remote element upon pivotal movement of said attachment in response to lengthening of the bucket cylinder.

3. The invention as claimed in claim 2, in which corresponding generally arcuate elements are provided on the side of said support means opposite said rst-men tioned arcuate elements, and are provided with similar tooth portions, and in which all of said elements are concave on their upper sides when said head is horizontally disposed.

4. ln combination with a backhoe having a boom and a dipper stick pivotally connected to said boom for pivotal movement in a vertical plane, a trench-digging bucket pivotally connected to said dipper stick remote from said boom for pivotal movement in said Vertical plane, said bucket being connected through actuator means with said dipper stick for pivoting of said bucket relative to said dipper stick in said vertical plane, said bucket cornpri'sing a plurality of narrow generally arcuate elongated elements disposed generally in said plane and having cutting portions at corresponding ends thereof, said arcuate elements being generally parallel to each other and being disposed for reception of earth therebetween upon pivotal movement of said bucket in said vertical plane, and means for supporting said elements in said generally parallel relationship While permitting discharge of earth from the spacesbetween said elements in at least one direction perpendicular to said vertical plane.

5. In combination with a backhoe having a boom and a dipper stick pivotally connected to said boom for pivotal movement in a vertical plane, a trench-digging bucket pivotally connected to said dipper stick remote from said boom for pivotal movement in said vertical plane, said bucket being connected through actuator means with said dipper stick for pivoting of said bucket relative to said dipper stick in said vertical plane, said bucket comprising a large thin plate disposed substantially in said plane, and a plurality of curved elongated elements mounted generally parallel to each other on one side of said plate and extending at least to an edge of said plate, the portion of each of said elements adjacent said edge of said plate being adapted for cutting of earth upon pivotal movement of said bucket in said plane, said elements being narrow and being disposed in a plane parallel to and adjacent said plate, the spaces between said elements being open for free discharge of earth in a direction perpendicularly away from said plate.

6. The invention as claimed in claim 5, in which at least portions of said curved elements are generally concentric with the pivotal connection which pivotally associates said bucket and said dipper stick.

7. in combination with a backhoe having a boom and a dipper stick pivotally connected to said boom for pivotal movement in a vertical plane, a trench-digging bucket pivotally connected to said dipper stick remote from said boom for pivotal movement in said vertical plane, said bucket being connected through actuator means with said dipper stick for pivoting of said bucket relative to said dipper stick in said vertical plane, said bucket comprising a relatively thin plate mounted substantially in said plane, and a plurality of narrow elongated earth-supporting elements mounted to said plate on opposite sides thereof and extending generally parallel thereto, there being at least two narrow` elements on each side of said plate, said elements being adapted at corresponding ends thereof to cut into earth upon pivotal movement of said plate relative to said dipper stick.

S. In combination with a backhoe having a boom and a dipper stick pivotally connected to said boom for pivotal movement in a vertical plane, a trench-digging bucket pivotally connected to said dipper stick remote from said boom for pivotal movement in said vertical plane, said bucket being connected through actuator means with said dipper stick for pivoting of said bucket relative to said dipper stick in said vertical plane, said bucket cornprising a head pivotally connected to said dipper stick and to said actuator means, a thin plate rigidly connected to said head in dependent relationship and disposed substantially in said vertical plane, and at least two narrow elongated earth-supporting strips xedly mounted on each side of said plate for support of earth thereon, said strips being provided with earth-cutting means at .corresponding end portions thereof, said strips extending suciently far from said cutting means to maintain a substantial quantity of earth between the two strips on each side of said plate, said strips being generally curved and parallel to each other and lying in planes which are parallel to said plate on opposite sides thereof.

9. The invention as claimed in claim 8, in which tbe spaces between said strips are open for free discharge of earth in directions perpendicularly away `from said plate.

l0. A trench-digging bucket attachment for a backhoe, comprising a head, a at plate connected to said head, and a plurality of generally arcuate narrow elongated earth-supporting strips disposed on each side of said plate in planes parallel thereto, there being at least two of said stn'ps adjacent each side of said plate and disposed in generally parallel relationship relative to each other, and tooth means provided at corresponding ends of said strips for cutting into earth to form a narrow trench, the spaces between said strips being open for free discharge of ear-th in directions away from said plate and perpendicular thereto.

References Cited in the le of this patent UNITED STATES PATENTS Cruse May 17, 1932 Dunternan Nov. 30, 1943 Schield Sept. 22, 1953` Pilch July 2l, 1959 Meredich Oct. 20, 1959 

